Is there an absorption interaction between ciprofloxacin (Ciproxin) and magnesium hydroxide (Emgesa

Fråga: Is there an absorption interaction between ciprofloxacin (Ciproxin) and magnesium hydroxide (Emgesan), or Omnibionta, a multiple vitamin?

Sammanfattning: There is a well examined drug absorption interaction between ciprofloxacin and bivalent and trivalent cations, such as the ones contained in Emgesan and Omnibionta. The mechanism is thought to be a chelation reaction between the 4-keto and 3-carboxyl groups on the ciprofloxacin molecule. It is recommended to not take ciprofloxacin, Emgesan, and Omnibionta simultaneously. However, if all three medications are essential, it could be recommended to take ciprofloxacin at least 2 hours before the other two.

Svar: Emgesan is magnesium hydroxide while Omnibiontia contains copper, magnesium, iron, manganese, zinc + calcium (1,2). The drug interactions of ciprofloxacin listed in the Swedish catalogue of approved medical products (FASS) are, among others: antacids containing calcium, magnesium or aluminum, as well as other calcium, zinc, and iron preparations (3). It is recommended that ciprofloxacin be taken at least two hours before calcium products, while concurrent administration of antacids, zinc, and iron products are not recommended (4).

Lehto et al demonstrated that concurrent ferrous sulphate ingestion with ciprofloxacin decreased peak plasma concentrations of ciprofloxacin by 57 per cent. The authors believe that ciprofloxacin and iron preparations should be separated by at least two hours (5).

This belief is also shared by Nix et al, Kara et al, and Neuvonen et al, who researched the absorption interaction between ciprofloxacin and aluminum/magnesium, iron preparations, and dairy products respectively (6-8). All of the authors concluded that ciprofloxacin levels are decreased when co-administered with these ion preparations and products. However, Kara et al also discovered that this phenomenon is also true with copper and manganese (7).

The proposed mechanism behind this circumstance is a chelation reaction that occurs between the cation itself and the 4-keto oxygen and 3-carboxylic acid groups of the quinolone (7). The ion-ciprofloxacin complex that is formed is insoluble and interferes with gastrointestinal absorption. In the case of iron sulphate, oxidation causes the formation of the trivalent ferric ion which binds in a ratio of 3:1 (7).